git.iko.soy/squeal
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move subquery expressions
d30ec04Eitan Chatav
squeal-postgresql/squeal-postgresql.cabal+1
compare with dev
unifiedsplit
@@ -35,6 +35,7 @@ library
35 Squeal.PostgreSQL.Expression.Null
35 Squeal.PostgreSQL.Expression.Null
36 Squeal.PostgreSQL.Expression.Parameter
36 Squeal.PostgreSQL.Expression.Parameter
37 Squeal.PostgreSQL.Expression.Sort
37 Squeal.PostgreSQL.Expression.Sort
38+ Squeal.PostgreSQL.Expression.Subquery
38 Squeal.PostgreSQL.Expression.Text
39 Squeal.PostgreSQL.Expression.Text
39 Squeal.PostgreSQL.Expression.TextSearch
40 Squeal.PostgreSQL.Expression.TextSearch
40 Squeal.PostgreSQL.Expression.Time
41 Squeal.PostgreSQL.Expression.Time
squeal-postgresql/src/Squeal/PostgreSQL.hs+2
@@ -207,6 +207,7 @@ module Squeal.PostgreSQL
207 , module Squeal.PostgreSQL.Expression.Null
207 , module Squeal.PostgreSQL.Expression.Null
208 , module Squeal.PostgreSQL.Expression.Parameter
208 , module Squeal.PostgreSQL.Expression.Parameter
209 , module Squeal.PostgreSQL.Expression.Sort
209 , module Squeal.PostgreSQL.Expression.Sort
210+ , module Squeal.PostgreSQL.Expression.Subquery
210 , module Squeal.PostgreSQL.Expression.Text
211 , module Squeal.PostgreSQL.Expression.Text
211 , module Squeal.PostgreSQL.Expression.TextSearch
212 , module Squeal.PostgreSQL.Expression.TextSearch
212 , module Squeal.PostgreSQL.Expression.Time
213 , module Squeal.PostgreSQL.Expression.Time
@@ -234,6 +235,7 @@ import Squeal.PostgreSQL.Expression.Math
234import Squeal.PostgreSQL.Expression.Null
235import Squeal.PostgreSQL.Expression.Null
235import Squeal.PostgreSQL.Expression.Parameter
236import Squeal.PostgreSQL.Expression.Parameter
236import Squeal.PostgreSQL.Expression.Sort
237import Squeal.PostgreSQL.Expression.Sort
238+import Squeal.PostgreSQL.Expression.Subquery
237import Squeal.PostgreSQL.Expression.Text
239import Squeal.PostgreSQL.Expression.Text
238import Squeal.PostgreSQL.Expression.TextSearch
240import Squeal.PostgreSQL.Expression.TextSearch
239import Squeal.PostgreSQL.Expression.Time
241import Squeal.PostgreSQL.Expression.Time
squeal-postgresql/src/Squeal/PostgreSQL/Expression/Subquery.hsnew file+110
@@ -0,0 +1,110 @@
1+{-# LANGUAGE
2+ DataKinds
3+ , OverloadedStrings
4+ , RankNTypes
5+ , TypeOperators
6+#-}
7+
8+module Squeal.PostgreSQL.Expression.Subquery
9+ ( exists
10+ , in_
11+ , notIn
12+ , subAll
13+ , subAny
14+ ) where
15+
16+import Squeal.PostgreSQL.Alias
17+import Squeal.PostgreSQL.Expression
18+import Squeal.PostgreSQL.Expression.Logic
19+import Squeal.PostgreSQL.List
20+import Squeal.PostgreSQL.Query
21+import Squeal.PostgreSQL.Render
22+import Squeal.PostgreSQL.Schema
23+
24+-- $setup
25+-- >>> import Squeal.PostgreSQL
26+-- >>> import Squeal.PostgreSQL.Render
27+
28+{- |
29+The argument of `exists` is an arbitrary subquery. The subquery is evaluated
30+to determine whether it returns any rows. If it returns at least one row,
31+the result of `exists` is `true`; if the subquery returns no rows,
32+the result of `exists` is `false`.
33+
34+The subquery can refer to variables from the surrounding query,
35+which will act as constants during any one evaluation of the subquery.
36+
37+The subquery will generally only be executed long enough to determine whether
38+at least one row is returned, not all the way to completion.
39+-}
40+exists
41+ :: Query (Join outer from) commons schemas params row
42+ -> Condition outer commons grp schemas params from
43+exists query = UnsafeExpression $ "EXISTS" <+> parenthesized (renderSQL query)
44+
45+{- |
46+The right-hand side is a parenthesized subquery, which must return
47+exactly one column. The left-hand expression is evaluated and compared to each
48+row of the subquery result using the given `Operator`,
49+which must yield a Boolean result. The result of `subAll` is `true`
50+if all rows yield true (including the case where the subquery returns no rows).
51+The result is `false` if any `false` result is found.
52+The result is `null_` if no comparison with a subquery row returns `false`,
53+and at least one comparison returns `null_`.
54+
55+>>> printSQL $ subAll true (.==) (values_ (true `as` #foo))
56+(TRUE = ALL (SELECT * FROM (VALUES (TRUE)) AS t ("foo")))
57+-}
58+subAll
59+ :: Expression outer commons grp schemas params from ty1 -- ^ expression
60+ -> Operator ty1 ty2 ('Null 'PGbool) -- ^ operator
61+ -> Query (Join outer from) commons schemas params '[col ::: ty2] -- ^ subquery
62+ -> Condition outer commons grp schemas params from
63+subAll expr (?) qry = expr ?
64+ (UnsafeExpression $ "ALL" <+> parenthesized (renderSQL qry))
65+
66+{- |
67+The right-hand side is a parenthesized subquery, which must return exactly one column.
68+The left-hand expression is evaluated and compared to each row of the subquery result
69+using the given `Operator`, which must yield a Boolean result. The result of `subAny` is `true`
70+if any `true` result is obtained. The result is `false` if no true result is found
71+(including the case where the subquery returns no rows).
72+
73+>>> printSQL $ subAll "foo" like (values_ ("foobar" `as` #foo))
74+(E'foo' LIKE ALL (SELECT * FROM (VALUES (E'foobar')) AS t ("foo")))
75+-}
76+subAny
77+ :: Expression outer commons grp schemas params from ty1 -- ^ expression
78+ -> Operator ty1 ty2 ('Null 'PGbool) -- ^ operator
79+ -> Query (Join outer from) commons schemas params '[col ::: ty2] -- ^ subquery
80+ -> Condition outer commons grp schemas params from
81+subAny expr (?) qry = expr ?
82+ (UnsafeExpression $ "ANY" <+> parenthesized (renderSQL qry))
83+
84+{- |
85+The result is `true` if the left-hand expression's result is equal
86+to any of the right-hand expressions.
87+
88+>>> printSQL $ true `in_` [true, false, null_]
89+TRUE IN (TRUE, FALSE, NULL)
90+-}
91+in_
92+ :: Expression outer commons grp schemas params from ty -- ^ expression
93+ -> [Expression outer commons grp schemas params from ty]
94+ -> Condition outer commons grp schemas params from
95+expr `in_` exprs = UnsafeExpression $ renderSQL expr <+> "IN"
96+ <+> parenthesized (commaSeparated (renderSQL <$> exprs))
97+
98+{- |
99+The result is `true` if the left-hand expression's result is not equal
100+to any of the right-hand expressions.
101+
102+>>> printSQL $ true `notIn` [false, null_]
103+TRUE NOT IN (FALSE, NULL)
104+-}
105+notIn
106+ :: Expression outer commons grp schemas params from ty -- ^ expression
107+ -> [Expression outer commons grp schemas params from ty]
108+ -> Condition outer commons grp schemas params from
109+expr `notIn` exprs = UnsafeExpression $ renderSQL expr <+> "NOT IN"
110+ <+> parenthesized (commaSeparated (renderSQL <$> exprs))
squeal-postgresql/src/Squeal/PostgreSQL/Query.hs−91
@@ -93,13 +93,6 @@ module Squeal.PostgreSQL.Query
93 , By (..)
93 , By (..)
94 , GroupByClause (..)
94 , GroupByClause (..)
95 , HavingClause (..)
95 , HavingClause (..)
96− -- * Subquery Expressions
97− , exists
98− , in_
99− , notIn
100− , Operator
101− , subAll
102− , subAny
103 ) where
96 ) where
104
97
105import Control.DeepSeq
98import Control.DeepSeq
@@ -1093,90 +1086,6 @@ instance RenderSQL (HavingClause outer commons grp schemas params from) where
1093 Having conditions ->
1086 Having conditions ->
1094 " HAVING" <+> commaSeparated (renderSQL <$> conditions)
1087 " HAVING" <+> commaSeparated (renderSQL <$> conditions)
1095
1088
1096−{- |
1097−The argument of `exists` is an arbitrary subquery. The subquery is evaluated
1098−to determine whether it returns any rows. If it returns at least one row,
1099−the result of `exists` is `true`; if the subquery returns no rows,
1100−the result of `exists` is `false`.
1101−
1102−The subquery can refer to variables from the surrounding query,
1103−which will act as constants during any one evaluation of the subquery.
1104−
1105−The subquery will generally only be executed long enough to determine whether
1106−at least one row is returned, not all the way to completion.
1107−-}
1108−exists
1109− :: Query (Join outer from) commons schemas params row
1110− -> Condition outer commons grp schemas params from
1111−exists query = UnsafeExpression $ "EXISTS" <+> parenthesized (renderSQL query)
1112−
1113−{- |
1114−The right-hand side is a parenthesized subquery, which must return
1115−exactly one column. The left-hand expression is evaluated and compared to each
1116−row of the subquery result using the given `Operator`,
1117−which must yield a Boolean result. The result of `subAll` is `true`
1118−if all rows yield true (including the case where the subquery returns no rows).
1119−The result is `false` if any `false` result is found.
1120−The result is `null_` if no comparison with a subquery row returns `false`,
1121−and at least one comparison returns `null_`.
1122−
1123−>>> printSQL $ subAll true (.==) (values_ (true `as` #foo))
1124−(TRUE = ALL (SELECT * FROM (VALUES (TRUE)) AS t ("foo")))
1125−-}
1126−subAll
1127− :: Expression outer commons grp schemas params from ty1 -- ^ expression
1128− -> Operator ty1 ty2 ('Null 'PGbool) -- ^ operator
1129− -> Query (Join outer from) commons schemas params '[col ::: ty2] -- ^ subquery
1130− -> Condition outer commons grp schemas params from
1131−subAll expr (?) qry = expr ?
1132− (UnsafeExpression $ "ALL" <+> parenthesized (renderSQL qry))
1133−
1134−{- |
1135−The right-hand side is a parenthesized subquery, which must return exactly one column.
1136−The left-hand expression is evaluated and compared to each row of the subquery result
1137−using the given `Operator`, which must yield a Boolean result. The result of `subAny` is `true`
1138−if any `true` result is obtained. The result is `false` if no true result is found
1139−(including the case where the subquery returns no rows).
1140−
1141−>>> printSQL $ subAll "foo" like (values_ ("foobar" `as` #foo))
1142−(E'foo' LIKE ALL (SELECT * FROM (VALUES (E'foobar')) AS t ("foo")))
1143−-}
1144−subAny
1145− :: Expression outer commons grp schemas params from ty1 -- ^ expression
1146− -> Operator ty1 ty2 ('Null 'PGbool) -- ^ operator
1147− -> Query (Join outer from) commons schemas params '[col ::: ty2] -- ^ subquery
1148− -> Condition outer commons grp schemas params from
1149−subAny expr (?) qry = expr ?
1150− (UnsafeExpression $ "ANY" <+> parenthesized (renderSQL qry))
1151−
1152−{- |
1153−The result is `true` if the left-hand expression's result is equal
1154−to any of the right-hand expressions.
1155−
1156−>>> printSQL $ true `in_` [true, false, null_]
1157−TRUE IN (TRUE, FALSE, NULL)
1158−-}
1159−in_
1160− :: Expression outer commons grp schemas params from ty -- ^ expression
1161− -> [Expression outer commons grp schemas params from ty]
1162− -> Condition outer commons grp schemas params from
1163−expr `in_` exprs = UnsafeExpression $ renderSQL expr <+> "IN"
1164− <+> parenthesized (commaSeparated (renderSQL <$> exprs))
1165−
1166−{- |
1167−The result is `true` if the left-hand expression's result is not equal
1168−to any of the right-hand expressions.
1169−
1170−>>> printSQL $ true `notIn` [false, null_]
1171−TRUE NOT IN (FALSE, NULL)
1172−-}
1173−notIn
1174− :: Expression outer commons grp schemas params from ty -- ^ expression
1175− -> [Expression outer commons grp schemas params from ty]
1176− -> Condition outer commons grp schemas params from
1177−expr `notIn` exprs = UnsafeExpression $ renderSQL expr <+> "NOT IN"
1178− <+> parenthesized (commaSeparated (renderSQL <$> exprs))
1179−
1180-- | A `CommonTableExpression` is an auxiliary statement in a `with` clause.
1089-- | A `CommonTableExpression` is an auxiliary statement in a `with` clause.
1181data CommonTableExpression statement
1090data CommonTableExpression statement
1182 (schemas :: SchemasType)
1091 (schemas :: SchemasType)